It is known to secure the engine block and the gear case of drive trains to each other, whereby it is important that a proper centering is accomplished in order to avoid uneven tensioning of the block and case.
German Patent Publication DE 4,002,791 A1 describes several possibilities of securing a gear case to one of the longitudinal sides of an engine block. According to one conventional version the engine block and the gear case are rigidly connected to each other at one end, while the other end is formed by a dovetail connection that permits an axial movement of the engine block and gear case relative to each other. Another conventional version employs a lever joint or mounting plates that are flexible in the direction of the longitudinal engine block axis, whereby different expansions of the engine block and the gear case are possible due to the influence of different temperatures. However, couplings using bolts and joints as just described have the disadvantage that either the required play cannot be achieved or that assembling the coupling is rather difficult because the proper or rather exact alignment of the engine block with the gear case is difficult. Where conventionally flexible plates are used for the coupling, it is possible to achieve a connection or coupling that is free of play. However, connecting the plates with screws has the disadvantage that the axial clamping forces cause uneven tensioning of the block and case due to positional and component manufacturing tolerances. Such uneven tensioning causes undesirable stresses.
German Patent Publication (DE-PS) 2,706,105 discloses a coupling of two engine housings or housing components to each other by a flange connection with clamping claws. It is an advantage of the just mentioned clamping claw connection that the assembly and disassembly can be accomplished quite simply because the clamping screws needed for the clamping claws are easily accessible. The clamping claws rigidly connect the engine block and the gear case to each other.
Another conventional clamping device or coupling device is described in German Patent (DE-PS) 898,982, wherein a tensioning arbor is used for clamping work pieces in a machine tool. The clamping is accomplished with two clamping elements on a mounting arbor, whereby the clamping elements mate with respective conical surfaces. By axially displacing the clamping elements by means of a clamping nut on the threaded arbor, the outer clamping element of the two clamping elements is radially expanded. In this manner a work piece surrounding the outer clamping element is fixed in position by radially effective clamping forces.